Project Summary/Abstract This project will improve the energy efficiency of home oxygen concentrators for patients on long-term oxygen therapy (LTOT) and save energy costs for the patients. The number of patients on LTOT is estimated to be 1.2 million. The cost of electricity can vary from one region, to another so it is difficult to determine the exact monthly cost of electricity to an oxygen patient. However, the energy usage for the average concentrator is similar to a refrigerator. Medical insurance does not reimburse for the cost of electricity used by the patient. These costs can be significant to the elderly on fixed incomes and patients at or below the poverty line. The phase I project will show the feasibility of advanced closed-loop control of the oxygen concentrator to improve energy efficiency. This SBIR responds to the NIH program announcement titled: Energy Efficiency and Renewable Energy System Technology Research and Development. This PA is a result of the Energy Independence and Security Act of 2007. PUBLIC HEALTH RELEVANCE: Project Narrative Approximately 1.2 million Americans are receiving long-term oxygen therapy in their homes. Most outpatient oxygen concentrators are designed to be inexpensive to manufacture.